Photophysical Studies in AOT Films Deposited on Fused Silica Slides

Thin surfactant films were made by dip-coating a fused-silica slide in reverse micelles of bis(2-ethylhexyl) sulfosuccinate sodium salt [AOT] in cyclohexane. The fluorescence quenching analysis of charge transfer between Ru(bpy)$^{2+}_3$ and MV2+, of resonance energy transfer between pyrene and coumarin-153, and of pyrene excimer formation has revealed that the original micellar structure is to a large extent transferred into the structure of the film. The film consists of a hydrophilic and a hydrophobic subphase. Nondried films contain entrapped cyclohexane which allows diffusion of the hydrophobic probes in the film and a rather random distribution of them. Drying leads to solvent evaporation and hydrophobic probe aggregation. The kinetics of the hydrophilic probes reflect the structure of the hydrophilic domain which is not affected by drying procedure. The above films are transparent matrices and make excellent hosts for photophysical studies.